Number of Lymph Nodes Examined and Prognosis of TNM Stage II Colorectal Cancer

Akira Tsunoda, Kentaro Nakao, Goichi Kamiyama, Kenshi Hiratsuka, Kazuhiro Narita, Katsuo Yamazaki, Makoto Watanabe, Naoto Suzuki, Naokuni Yasuda and Mitsuo Kusano

Department of General and Gastroenterology, Showa University School of Medicine

Purpose: The diagnosis of lymph-node-negative colorectal cancer should imply a good prognosis, but the outcome for TNM stage II patients remains spotty. We determined whether the number of lymph nodes found affects this prognosis. Materials and Methods: Data on TNM stage II or III patients who underwent surgery for colorectal cancer between 1981 and 2000 was taken from a database and surgery compared using Kaplan-Meier curves and the log-rank test. Multivariate analysis was conducted using a Cox regression model. Results: We analyzed 229 TNM stage II cases and, for comparison, 204 stage III cases. Lymph node retrieval in stage II cases was affected by patient age (P=0.0035), emergency operation (P=0.0010), and tumor site (P=0.0030). In stage III cases, lymph node retrieval was affected by gender (P=0.0108) and invasion depth (P=0.0085). Decreased lymph node detection was associated with an increased hazard ratio among 229 TNM stage II patients. Five-year survival for patients with stage III tumors with only 1-3 positive lymph nodes (61.6%) was similar to that of patients with stage II tumors who had 11 or fewer lymph nodes (68.5%). Conclusions: The prognosis of TNM stage II colorectal cancer depends on the number of lymph nodes found and, presumably those with stage II tumors and only a few nodes found routinely be provided postoperative chemotherapy.

Key words
colorectal cancer, survival, prognosis, lymph node assessment, staging

Reprint requests
Akira Tsunoda Department of General and Gastroenterological Surgery, Showa University School of Medicine
1-5-8 Hatanodai, Shinagawa-ku, 142-8666 JAPAN

Accepted
November 30, 2005

To read the PDF file you will need Abobe Reader installed on your computer.